Automatic grader stabilizer

ABSTRACT

A method of stabilizing a small to mid-sized skid steer vehicles used to grade earth using a dozer blade in conjunction with GPS automatic grade control equipment. The main arm of the skid steer is retained at a specific height and the hydraulic controlling the main arm is limited. The height of the dozer blade is raised and lowered by affecting the pitch axis of movement of the blade and not by raising and lowering the main arm. The device is most suited to skid steer vehicles capable of using a variety of interchangeable front end accessories in addition to a dozer blade.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to earth moving equipment, and moreparticularly, to an improved earth moving grader stabilizer.

2. Description of the Related Art

Several designs for improvements to earth moving equipment have beendesigned in the past. None of them, however, includes a device thatstabilizes an earth moving grader blade of small to medium-sizedtrack-steer or skid-steer vehicles using a remote grade controllersystem.

Applicant believes that the closest reference corresponds to U.S. Pat.No. 8,118,111 issued to Armas. However, it differs from the presentinvention because the Armas method attempts to stabilize the dozer bladeby a brackets locking the pitch axis movement of the dozer blade with abracket locking relative movement between the main arm of the vehicleand the attachment comprising the dozer blade assembly. The Armas priorart maintains the full movement of the main arm of the vehicle to raiseand lower the attachment assembly including the dozer blade.

The limitations of this method rests in the requirement for theautomatic grading system to finely adjust the grade height of the bladeby using the large hydraulics of the main arm to lift and lower theentire dozer blade assembly along with the up and down movements of themain arm. This creates a lot of weight being moved continually up anddown as the blade automatically is adjusted by the automatic gradesystem which has the limitations of using significant power, impartingstress on the greater structure of the skid steer vehicle, slowsmovement with greater mass being moved and reduces the fineness of theresolution that the cutting edge of the blade can be held duringautomatic grading operations.

The Armas system is very effective when used with an automatic lasergrading systems as disclosed in his '111 patent. The laser system isguided by a laser receiver mast affixed to the dozer blade to measureand calibrate the controlled movements of the vertical position of thedozer blade during automatic grading operations. For this to beeffective the blade must generally be held vertically to ensure that thelaser mast is generally vertical. Tilting of the mast off from avertical position would impart an error to the system causing theautomatic controller to misinterpret the actual height of the bottom ofthe dozer blade relative to the earth being moved.

However, with the advent of higher resolutions with the wide areaaugmentation system global positioning system (WAAS-GPS) the laser mastis no longer required in all automatic grading systems. The limitationcreated by a tilting mast that can confuse the accuracy of a lasergrading system is no longer a factor for these systems. The location ofthe blade can be derived by satellite and the height of the bladecalibrated for consistent and accurate automatic grading.

The present device and method stabilizes the dozer blade attachmentassembly by limiting the main arm of the vehicle axis of movement. Thisprovides a stable platform for the dozer blade attachment assembly thatin turn which permits greater control of the blade and stabilizes theblade for more precise control. This and other features are described inmore detail below.

Other patents describing the closest subject matter provide for a numberof more or less complicated features that fail to solve the problem inan efficient and economical way. None of these patents suggest the novelfeatures of the present invention.

A brief abstract of the technical disclosure in the specification andtitle are provided as well for the purposes of complying with 37 CFR1.72 and are not intended to be used for interpreting or limiting thescope of the claims.

Without limiting the scope of the invention, a brief summary of some ofthe claimed embodiments of the invention is set forth below. Additionaldetails of the summarized embodiments of the invention and/or additionalembodiments of the invention may be found in the detailed description ofthe invention below.

SUMMARY OF THE INVENTION

It is one of the main objects of the present invention to provide adevice that grades a wide variety of soil types and site conditions in ahighly accurate way.

Another object of the present invention is to provide a stable platformon a medium to small skid steer vehicle that does not need the use of alaser mast affixed to the dozer blade but instead adapts the vehicle tobe suitable for GPS automatic laser grading systems.

It is another object of the present invention that does not require anyadditional ground contacting stabilizers.

It is another object of this invention to provide a device that canmaneuver in restricted space and around sensitive objects andsubstrates.

It is still another object of the present invention to provide greaterfunctionality to small to medium skid steer and track steer vehicleswhile retaining their ability to be used with the wide variety ofavailable accessories.

It is yet another object of this invention to provide such a device thatis inexpensive to manufacture, light weight and easy to maintain whileretaining its effectiveness.

Further objects of the invention will be brought out in the followingpart of the specification, wherein detailed description is for thepurpose of fully disclosing the invention without placing limitationsthereon.

These and other embodiments which characterize the invention are pointedout with particularity in the claims annexed hereto and forming a parthereof. However, for a better understanding of the invention, itsadvantages and objectives obtained by its use, reference can be made tothe drawings which form a further part hereof and the accompanyingdescriptive matter, in which there are illustrated and described variousembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

With the above and other related objects in view, the invention consistsin the details of construction and combination of parts as will be morefully understood from the following description, when read inconjunction with the accompanying drawings in which:

FIG. 1 is a side elevation view of a track steer vehicle with a dozerblade in a lower position.

FIG. 2 is a side elevation view of a track steer vehicle with a dozerblade in an upper position.

FIG. 3 is a front elevation view demonstrating blade roll counterclockwise.

FIG. 4 is a front elevation view demonstrating blade roll clockwise.

FIG. 5 is a top plan view demonstrating blade yaw left.

FIG. 6 is a top plan view demonstrating blade yaw right.

FIG. 7 is a side elevation view demonstrating a raised main arm.

FIG. 8 is a side elevation view demonstrating lowered main arm and analternate example of bracket.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While this invention may be embodied in many different forms, there aredescribed in detail herein specific embodiments of the invention. Thisdescription is an exemplary of the principles of the invention and isnot intended to limit the invention to the particular embodimentsillustrated and described.

For the purpose of this disclosure, like reference numerals in thefigures shall refer to like features unless otherwise indicated or isobvious by context.

The subject device and method of use is sometimes referred to as thedevice, the invention, the dozer, the automatic grader, the skid steer,the bracket, the GPS grader, the machine, the system, the method orother similar terms. These terms may be used interchangeably as contextrequires and from use the intent becomes apparent. The masculine cansometimes refer to the feminine and neuter and vice versa. The pluralmay include the singular and singular the plural as appropriate from afair and reasonable interpretation in the situation.

Skid steer vehicles are commonly commercially available. The skid steervehicle that is preferred to work with the present device is small tomedium sized and designed to accept any of a variety of front endaccessories such as a dozer blade, pallet forks, a mower, a hole diggerand several others. These front end accessories can be interchangedrelatively easy with one or two men in a few minutes. The popularity ofthe small to medium sized skid steer class of vehicle is owed largely tothe availability of the front end accessories by allowing a singlevehicle to accomplish a wide variety of tasks without the need forspecialty vehicles.

Grade control systems, such as laser automation, are commonlycommercially available. Many early systems worked with a laser referencebeacon erected on an edge of a job site at a known location andelevation established by survey. A laser receiver is attached toearthmoving equipment, typically onto the ground contacting blade, andsends a signal to a computer accessible to the operator of theearthmoving equipment. The computer is able to determine if the blade isabove or below the desired grade and make adjustments as necessary tothe blade height by controlling the hydraulics that move the blade.

However, the automatic grade control systems have evolved to utilizehighly accurate GPS signals in combination with computer control modulesto automate the height of the dozer blade as the vehicle moves over thejob site. Laser control masts are no longer needed to maintain theaccuracy of earlier machines.

With the prior art laser control systems the dozer blade supported thelaser control receiver mast. This mast had to be held upright, nearlyvertical, consistently so that the system could use the top of the mastas a datum for referencing the height of the bottom of the dozer bladethe defined the grade being made as the dozer moved over the earthdefining the new grade.

Earlier solutions kept the blade and therefore the laser mast verticalby preventing the pitch axis of movement of the dozer blade. This keptthe mast vertical. However, the height of the dozer blade was thencontrolled by the vertical movement of the main arm that also carriedthe entire dozer blade assembly.

The dozer blade assembly with the several hydraulic actuators, dozerblade, hoses, frame and other elements, along with the main arm itselfis very heavy. This uses substantial energy to move and has a potentialfor slowed and jerky movements that can affect the precision andsmoothness of the grade.

The solution generally is found when the laser mast is no longer neededbecause GPS has been employed to control the automatic grade computerlocation and the required grade relative to that location. Without thelaser mast the dozer blade, previously restricted in pitch movement, cannow be freed to adjust as necessary to control the bottom of the dozerblade defining the surface grade.

However, it has been determined through much trouble and experimentationthat when the main arm is available to control the height of the bottomof the dozer blade while the pitch axis of the blade is simultaneouslyadjusting the height of the bottom of the blade that a consistent gradecannot be consistently achieved. This is particularly so when there arevarying densities of soil substrates that are being graded with thedozer blade.

A solution at the heart of the present invention is to secure the heightof the main arm so that when the dozer blade is vertical the bottom ofthe dozer blade is at a predetermined height relative to the preexistinggrade as generally defined as the plane on which the dozer tracks ride.

With the advent of highly accurate GPS and related positioning systemsthe laser reference is no longer needed to be affixed to the top of theblade. This now allows the pitch axis, or forward tilt of the dozerblade to be moved without adversely affecting a laser control system andthereby freeing earlier limitations.

Referring now to the drawings, where the present invention is generallyreferred to with numeral 10, it can be observed that it basicallyincludes a tractor assembly 12, an operator cage 14, an engine case 16,a track assembly 18, a suspension 20, a track 22, a hinge 24, a hinge26, a hinge 28, a blade assembly 30, a hydraulic 32, a hydraulic 34, ahydraulic 36, a hydraulic 38, a frame 40, an antennae 42, a frame 44, ablade 46, a main arm 48, a valve 50, a front 52, a bottom 54, a bracket56, a stop 58, a body 60 and a lock 62 and a leveler assembly 80.

Said tractor assembly 12 comprises, inter alia, an operator cage 14 andan engine case 16. An operator of the vehicle sits inside of andoperates the vehicle from inside the operator cage 14. An engine insidethe engine case 16 typically powers the vehicle including any hydraulicsand an electrical system that powers the native on-board computercontrol system of the skid steer. Essentially the electronic controls ofmodern skid steer vehicles are fly-by-wire. Electrical inputs from ajoystick are processed by the native computer and operate a system ofsolenoids, actuators, valves and other components to then control thehydraulic system that ultimately supplies the force to move the variouselements of the skid steer and the operative attachments, such as adozer blade assembly.

Said track assembly 18 comprises, inter alia, a suspension 20 and atrack 22. In most applications a track steer vehicle will havecomplementary track assemblies 18 on both sides of the vehicle. Thepresent system will work equally well on a wheeled vehicle and is notdependent on the form that the small earth moving vehicle embodies.However, a skid steer is commonly utilized with the present invention onmany job sites and is well suited to move earth.

Said blade assembly 30 comprises, inter alia, a hydraulic 32, ahydraulic 36, a hydraulic 38, a frame 40, a bracket 42, a frame 44, ablade 46 and a main arm 48. The blade assembly 30 can generally beremoved from the skid steer to use another attachment, as noted above.

Some users of the present system find it so indispensable that effortsare taken to permanently affix the blade assembly 30 to the skid steerand essentially make it a one purpose vehicle. Some of these adaptionsuse welding to affix the blade assembly to the front of the skid steer.The remaining axis of movements should be retained so that the automaticgrade system keeps the full functionality with which it was designed touse.

FIG. 1 is an elevation view of a skid steer vehicle with a bladeassembly 30 attached operatively to the front. Importantly, the front 52of the main arm 48 is resting on the stop 28. This positions the mainarm 48 in the lower most position. The main arm 48 cannot go lowerbecause the stop 28 limits its downward movement.

The stop 28 is located on the body 60 of the skid steer or otherlocation where the stop 28 is determined to intersect the front 52 orother part or bracket associated with the main arm 48 to limit itsmovement. Essentially the main arm 48 rests with the weight of the mainarm 48 securely held by the stop 28.

The combination of stop 28 resting on the front 52 is merely enablingand exemplary of any combination where the main arm 48 bottoms out on astructure that supports the weight of the main arm 48 so that the mainarm 48, and the blade assembly 30 affixed thereto so that the bottom 54of the blade 46 is at a selected height relative to the level of theground upon which the tracks 22 are supported.

As seen in FIGS. 1 and 2, when the main arm 48 is fully down the mainarm 48 is against the stop 28 and locked against the stop with the lock62. The lock 62 connects the main arm 48 (or an appendage thereto)against the body 60 (or appendage thereto) so that the main arm 48 isunable to move up or down. To further inhibit movement of the main arm48, when the lock 62 is secure the valve 50 providing hydraulic pressureto the hydraulic 32 to move the arm is closed effectively stopping anymovement of the main arm 48 by an additional means.

By having the valve 50 present the machine can easily be reconfiguredwith an alternate front attachment that utilizes the movement of themain arm 48, for example, a dump bucket, auger or any other attachment.When the other attachment is connected the valve 50 is simply opened andthe lock 62 is removed and full functionality of the main arm 48 isrestored.

With the valve 50 the user contemplates returning the skid steer tofunction with attachments other than only the dozer blade. In accordwith this intent, the lock 62 is preferably also unlockable to free themovement of the main arm 48. The lock may therefore be comprised of abracket like structure removably fixing the main arm 48 in position.Similarly, the lock 62 could manifest as a pinning system, boltingsystem or other similar means to connect the main arm 48 with the body60 ans substantially preventing movement of the main arm 48 when thelock 62 is secured and the hydraulic 32 is rendered ineffective.

In some versions of the application of the inventive concept the valve50 is not needed because the operator of the vehicle opts to dedicatethe machine more fully to the GPS automatic grading. In this option, thehydraulic 32 is disconnected by capping the supply and or returnhydraulic lines that feed hydraulic 32. This effectively stops anymotive force affecting the raising and lowering the main arm 48 so thelock 62 secures the main arm 48 unopposed. With the hydraulic supply tohydraulic 32 removed there is no need for a valve 50.

In yet another variation that fully and essentially permanentlydedicates the machine to GPS automatic grading the main arm 48 may bewelded to the body or other structure of the vehicle to permanently lockthe main arm 48 in place. The hydraulics 32 affecting the main arm 32may be disabled or removed entirely. This option may be attractive tosome users because it may be cheaper to install if the skid steer willnever be used with the main arm 48 functional. In this version lock 62would also be unnecessary because the weld would hold the main arm 48 ina secure position.

Referring now to FIG. 2 where the same vehicle is shown as in FIG. 1 butnow shows the hydraulic 34 in a contracted configuration compared to theextended mode in FIG. 1. The difference between FIGS. 1 and 2 isexaggerated in these renderings to show that by changing the degree towhich the hydraulic 34 is extended or retracted that the distance thatthe bottom 54 of the blade 46 lowers or raises relative to the plane ofthe ground defined by the bottom level of the tracks.

It is exactly this movement of the bottom 54 of the blade up and downthat controls the depth of the cut of the blade as controlled by theautomatic GPS grading computer. In the prior art the main arm had tolift the whole blade assembly 30 to move the bottom 54 up and down. Now,with the main arm 48 locked only the pitch up of the blade 46 affectshow deep the blade 46 cuts the soil. The GPS computer controls thisdepth and thereby controls the grade that the machine levels the soil.Notice how the weight of the main arm 48 no longer is needed to movewith the rest of the blade assembly 30 when the height of the bottom 54is manipulated by the automatic grading computer.

As the hydraulic 34 picks up and lowers the blade 46 and its bottom 54the entire blade assembly 30 is articulated about hinge 24. The roll andyaw movements described below are still maintained effective and canalso be optionally controlled by the automatic grading computer systemindependent of the pitch axis of movement.

It should be appreciated that there are alternative configurations ofequivalents of the blade assembly 30 than the illustration provided withthis specification. In some, the entire blade assembly 30 may not liftand lower with the pitch hydraulic 34 because the pitch hydraulic 34 maybe, for example, directly connected to the blade 46 so that fewerelements than the whole blade assembly 30 must be moved together. Theinventive concept includes that the main arm 48 is not responsible forthe lifting of the bottom 54 but instead is the hydraulic, functionallysimilar to hydraulic 34, that controls the pitch movement of the blade46 that has the effect of altering the height of the bottom 54.

Now referring to FIGS. 3 and 4 where a front elevation view of a skidsteer vehicle with a dozer blade attachment is shown. These views are todemonstrate the roll axis that the operator of the vehicle can move theblade. The roll axis is typically manipulated to produce an incline orsloped grade. The roll axis is controlled by hydraulic 36.

FIGS. 5 and 6 are a top plan view of a skid steer vehicle with a dozerblade attachment demonstrating the yaw axis that the operator of thevehicle can move the blade. The yaw axis is typically changed to pushsoil to one side of the skid steer vehicle. The change in yaw can behelpful in moving soil as part of the grading process. The yaw axis iscontrolled by hydraulics 38.

FIG. 7 shows an example of the main arm 48 in a lifted configuration byextending the hydraulic 32. In this configuration the lock 62 isunlocked and the valve 50 is open allowing normal operation of the mainarm 48 as the machine was intended from the manufacturer. FIG. 7 is notconfigured in accord with the present inventive concept whilefunctioning to automatic grade. This figure merely demonstrates thecapability of the machine when the present method of stabilizing theautomatic grading system is not employed. In at least some versions ofthe invention the machine can easily be reconfigured to work as in FIG.7 as might be needed for purposes other than GPS automatic grading whilethe valve 50 is open and the hydraulic 32 is active and the lock 62 isnot securing the main arm 48.

FIG. 8 is a side elevation view of a skid steer vehicle with a dozerblade attachment demonstrating an alternate but equivalent means tosecure the main arm 48 in a stable position. As discussed above, thehydraulic 32 is disabled by closing valve 50 or by the other hydrauliclimiting means. In this version there is a bracket 56 affixed to themain arm 48 or other structure appurtenant thereto that interfaces witha stop 58 associated with the body 60 or other structural part of thevehicle. The combination of bracket 56 and stop 58 define a specificposition that the main arm 48 is held at during the GPS automaticgrading operations.

The use of the bracket 56 and stop 58 allow any brand, shape orconfiguration of skid steer to have a means to hold the main arm 48 atthe required position to in turn hold the blade assembly 30 at the rightheight so that only the pitch axis of movement of the blade 46 affectshow deep the blade 46 cuts and the automatic grading computer caneffectively cut throughout the range of blade height needed.

The bracket 56 and stop 58 may be bolted or welded on the measuredposition of the machine and its main arm 48 so that the bottomed outmain arm 48 is held at the right height. This may vary from make ofmachine to different models of the same make. A lock 62 is alsooptionally provided to secure the main arm 48 in place during automaticgrading operations similar to the lock on other embodiments as disclosedin the examples given above.

Also similar to other versions above, the bracket 56 and stop 62 may bea plate, bracket or other structure securing more permanently the mainarm 48 to the structure of the vehicle. Likewise the valve 50 could betraded for other means to prevent activation of the hydraulic 32 inaddition to the bracket 56 and stop 58.

One commonly skilled in the art will appreciate a small to medium skidsteer vehicle as contrasted to a larger dedicated purpose earthmovingvehicle such as a bulldozer.

One commonly skilled in the art will appreciate a small to medium skidsteer vehicle may have either ground contacting tracks or wheels. Inmost environments a track style small to medium skid steer vehicle ispreferred for its stability, traction and resistance to sinking insofter soils or creating ruts.

It should be appreciated that the inventive concepts can be maintainedby including some or all parts from different variations of theembodiments described herein. The drawings are not intended to bespecifically limiting to a single configuration giving rise to theinventive concept but are instead stylized illustrations of theimportant functions and features that may be encompassed in the greaterinventive intent as apparent by this disclosure.

An important version of the invention can be fairly described as 1. Amethod for controlling a dozer blade controlled by an automatic gradecontrol system on a skid steer vehicle comprising providing a skid steervehicle having a main arm with a front side operably coupled to a dozerblade assembly. The skid steer is otherwise generally capable of havingother front end attachments for other types of jobs. Then providing astop connected to the skid steer vehicle upon which a point of the mainarm rests thereby defining a lower limit of movement of the main arm.Essentially the main arm bottoms out at a preset height that iscomplimentary of the proper height that the dozer blade needs to be forits auto grading purposes. A bracket may be used to rest the main armagainst or in some skid steer vehicles the body of the machine is at theappropriate height. A bracket and stop combination can be used to adaptany machine to bottom out at the right height for the pitch of the bladealone to control the continuous auto grading. Also, positioning thepoint of the main arm against the stop so it is bottomed out. Also,preventing the ability of the main arm from providing any lifting forceby restricting the ability of a hydraulic that lifts the main arm. Thisessentially neuters the ability of the main arm to move up under powerof the hydraulic that could normally otherwise lift the main arm. Also,operably connecting the automatic grade control system to a hydraulicthat controls a pitch axis of movement of the dozer blade to affect aheight of the dozer blade relative to a ground surface. The pitch axisof movement of the blade is this used to raise and lower the gradeheight as controlled by the automatic grading computer system. Themethod may further include locking the main arm against the stop whenthe main arm is at the lower limit of movement of the main arm. This canbe by bracket, bolt, welding, pins, chains, clamp or other positivemeans to hold the main arm in place at its lowest allowed position asdetermined by the stop. The method may further including operating avalve to hydraulically isolate (hydraulically disconnect) the hydrauliclift actuator that lifts the main arm to further prevent any movement ofthe main arm. This essentially disconnects the main arm control from thesystem. This can also be achieved by disconnecting and capping off thehydraulic control for the main arm or by removing that hydraulic controlcompletely.

The foregoing description conveys the best understanding of theobjectives and advantages of the present invention. Differentembodiments may be made of the inventive concept of this invention. Itis to be understood that all matter disclosed herein is to beinterpreted merely as illustrative, and not in a limiting sense.

What is claimed is:
 1. A method for controlling a dozer blade controlledby an automatic grade control system on a skid steer vehicle comprising:providing a skid steer vehicle having a main arm with a front sideoperably coupled to a dozer blade assembly; providing a stop connectedto the skid steer vehicle upon which a point of the main arm reststhereby defining a lower limit of movement of the main arm; positioningthe point of the main arm against the stop; preventing the ability ofthe main arm from providing any lifting force by restricting the abilityof a hydraulic that lifts the main arm; operably connecting theautomatic grade control system to a hydraulic that controls a pitch axisof movement of the dozer blade to affect a height of the dozer bladerelative to a ground surface.
 2. The method for controlling a dozerblade as in claim 1 further including: locking the main arm against thestop when the main arm is at the lower limit of movement of the mainarm.
 3. The method for controlling a dozer blade as in claim 1 furtherincluding: operating a valve to hydraulically isolate the hydraulic liftthat lifts the main arm to further prevent any movement of the main arm.4. The method for controlling a dozer blade as in claim 3 furtherincluding: locking the main arm against the stop when the main arm is atthe lower limit of movement of the main arm.